Lipids and Proteins Flashcards
Animal Fat Examples
meat, cheese, dairy
Plant Fat Examples
vegetable oils, nuts, avocados
Hidden Fat Examples
French fries, pizza, pasta dishes, baked goods, salad dressings
Some Benefits of lipids and fats
Provide texture, flavor, aroma to foods
Structural materials of cellular membranes
Wraps Nerve Fibers (mylin)
Help absorb fat-soluble vitamins
Insulate, cushion, lubricate
Provide energy
What does fat tissue store?
Triglycerides
fat is ____kcal.
carbs are ____kcal.
9kcal
4kcal
What happens to excess fat?
Broken down into fatty acids and stored by the liver as triglycerides.
What are two important ingredients for making ATP?
Triglycerides: the storage form of fatty acids
kept in fat cells and in smaller amounts in muscle cells
Glycogen: the storage form of carbohydrates
kept in both muscle cells and in liver cells
Chased by a bear: ATP
1-2 seconds: All stored ATP is used up.
10-15 seconds: ATP-PCr system for an all-out sprinting.
1-2 minutes: Glycolytic pathway keeps you going for but at a slower pace.
Several minutes, even hours Oxidative phosphorylative pathway keeps you going BUT at a much slower pace.
What was the old view of fats?
eating fat makes you fat
saturated fats = coronary heart disease
Health regulators promoted low-fat products & to reduce the intake of natural fats
1980’s low-fat high-carb diets recommended
What is the current view of fats?
foods naturally rich in fats (in small portions) are good for you
regulation of appetite and overall body composition.
High and low sources of lipids in our diet
100% - Butter, salad dressing, mayo, margarine.
15% - Bread and bagels.
Health Canada’s AMDR for lipids is…
25-35%
What are lipids?
Lipids are ‘fatty acids’ made up of molecules of carbon & hydrogen.
Saturated fatty acids are _______ at room temp because…
Unsaturated fatty acids are _______ at room temp because…
solid because more hydrogen ions.
liquid because less hydrogen ions.
Do lipids dissolve in water?
No.
Monounsaturated fatty acids
contain one double bond along the carbon chain.
Polyunsaturated fatty acids
contain two or more double bonds along the carbon chain.
Saturated Fat make-up
packed closely together
all carbon bonds
balanced
Unsaturated Fat make-up
“bent hockey stick”
double hydrogen missing
one double carbon bond
Match
Newspaper
Wood
Creatine
Carbohydrates
Fat
Why are Omega 3’s essential?
anti-inflammatory
dilates blood vessels & reduce blood clotting
Supports brain function
Eases symptoms of depression, anxiety
Benefits vision, immune system, skin, hair
What are 3 Omega 3’s?
Alpha-linolenic acid (ALA) Eicosapentaenoic acid (EPA) Docosahexaenoic acid (DHA)
ALA
It is mostly found in plant foods.
Your body can convert it into EPA or DHA, though this process is highly inefficient (used for energy)
Example: kale, spinach, soybeans, walnuts, and many seeds, such as chia, flax, and hemp. It also occurs in some animal fats.
EPA
It is an omega-3 fatty acid that can reduce symptoms of depression and help fight inflammation in your body.
EPA & DHA mostly found in seafood, including fatty fish and algae
DHA
It is very important for brain development and may protect against heart disease, cancer, and other health problems.
EPA & DHA mostly found in seafood, including fatty fish and algae
Omega 6
Linolenic Acid
Pro-inflammatory
Constricting Blood vessels & blood clotting
important for healing injuries & recovery from training
Caution in over-consuming Omega 6!
It is easy to consume Omega 6 in the diet.
What is the ratio of consumption for Omega 3 and 6?
People end up having a 1:16 ratio.
People should try to get the ratio to 1:4.
Farmed salmon vs wild salmon.
Farmed = omega 6, higher in fat, fed pellets. wild = omega 3, less fatty, feeds on krill.
The body can make all but how many types of fatty acids?
2.
What are we unaware of in our diet?
Soybean oils.
Phospholipids
Our body can make these: non-essential amino acids.
water and fat mixed
Similar structure to triglycerides (built on glycerol)
Phospholipids exist throughout the body, particularly in the brain
They participate in fat digestion and play an important structural role in cell membranes
What are 2 identifications of lipids?
Phospholipids and Sterols.
Sterols —- Cholesterol
Plants: in the cell membrane
Animals: Cholesterol, non-essential. Made in the liver, therefore it is nonessential
Used to make: Cell membranes Myelin Vitamin D Bile acids Cortisol, testosterone, estrogen
Trans Fatty Acids
The orientation of hydrogen atoms around the double bond distinguishes cis fatty acids from trans fatty acids.
Most unsaturated fatty acids found in nature have double bonds in the cis configuration.
LDL
LDL (low density lipoproteins) = ‘bad’ cholesterol
Triglycerides
Your LDL, the unhealthy cholesterol, should be under 100 mg/dl
HDL
HDL (high density lipoproteins) = ‘good’ cholesterol
Lowers triglycerides (helps rid the body of the bad LDL cholesterol)
Your HDL, the healthy cholesterol, needs to be 50 mg/dl or more
Densest Lipoprotein based on their high protein.
Lipoproteins
Chylomicron and VLDL’s
Chylomicron
Largest lipoproteins and contain the most triglycerides.
VLDL’s
smaller than Chhylomicron, still contain a lot of triglycerides.
Good Lipids (unsaturated)
Virtually all plant lipids
Nuts & Seeds
Fish
Bad Lipids (saturated)
Dairy fat
Animal fat
Very Bad Lipids!
Partially hydrogenated
Trans fats
Hydrogenation
Partial hydrogenation produces a ‘semi-solid lipids’ product
Hydrogenation produces “solid lipids”
Increases LDL cholesterol (bad) & decreases HDL (good)
When did Health Canada ask that trans fats be listed on the labels?
Trans Fats now listed on nutritional labels (2005)
2007, Health Canada called on food manufacturers to voluntarily reduce the amount of trans fat in their products to less than 5% of total fat.
limit consumption of:
Fried foods, pastries, pie, flaky bread products (croissants), crackers, biscuits… and donuts!
What is the limit we should have for saturated fats in our diet?
10%
The other 90% should come from unsaturated fats.
Avoid trans-fats and partially hydrogenated oils.
How do proteins get broken down?
Proteins –> tripeptides –> dipeptides –> amino acids
How do proteins get absorbed?
Mechanical digestion: in the mouth, stomach, and small intestine.
Chemical digestion: stomach and small intestine.
What breaks down protein in the stomach?
Hydrochloric acid and the enzyme pepsin.
What breaks down protein in the small intestine?
Protein-digesting enzymes from the pancreas along with microvilli.
Polypeptides –> amino acids
tripeptides –> dipeptides (can enter the mucosal cell and will be further broken down into amino acids)
Once in the mucosal cell, where do proteins go?
into the blood, transported to the liver to be regulated to the rest of the body.
Stomach
What does hydrochloric acid do to proteins?
What does stomach acid trigger the release of?
It denatures them.
polypeptide chains are more accessible for an enzymatic breakdown.
Triggers the release of pepsin.
Digestion of proteins in the small intestine.
Polypeptides are broken into smaller peptides and amino acids.
Protein digesting enzymes from the pancreas break them down.
What absorbs through the Mucasol cells?
single amino acids, dipeptides, and tripeptides are absorbed.
absorbed into the mucosal cells then into the blood
USES energy-requiring amino acid transport systems.
What is in Pancreatic juice?
Bicarbonate: neutralizes the acid in the chyme (from the stomach)
Pancreatic amylase: digests carbohydrates into sugars
Pancreatic proteases: digests proteins into amino acids
Pancreatic lipases: digests fats into fatty acids
How does the liver aid in digestion?
The liver secretes bile which emulsifies fat (breaks down droplets) so lipases can access fat molecules.
How does the brush border aid in digestion?
Brush border secretes enzymes that complete the digestion of carbohydrates and proteins.
Small Intestine Chemical Digestion
- Pancreatic amylase digests starch to double sugars and short glucose chains.
- Fiber, which cannot be digested by human enzymes, passes to the large intestine.
- Enzymes in the microvilli digest double sugars into single sugars, which are absorbed into the blood.
- Pancreatic proteases, along with proteases in the microvilli, digest long amino acid chains into amino acids and short amino acid chains.
- Amino acids and short amino acid chains are absorbed into the mucosal cells, where they are digested into single amino acids, which pass into the blood.
- Bile helps divide large fat globules. Pancreatic lipases digest (at molecules into fatty acids.
- Short-chain fatty acids are absorbed into the mucosal cells and then pass directly into the Wood.
- Long-chain fatty acids and other lipids combine with bile to form small droplets that aid the absorption of fatty acids and other fat-soluble substances into the mucosal cell.
- Absorbed lipids are incorporated into transport particles that pass into the lymph. They enter the blood without first passing through the liver.
What is the function of the lymphatic system
maintains the balance of fluid between the blood and tissues, known as fluid homeostasis.
forms part of the body’s immune system and helps defend against bacteria and other intruders.
facilitates the absorption of fats and fat-soluble nutrients in the digestive system
The lymphatic system consists of lymph vessels, ducts, nodes, and other tissues.
Animal Proteins
meat, eggs, dairy products
High in saturated fat and cholesterol
Provide B vitamins (*B12) and some absorbable minerals
Contain all 9 “essential” amino acids
Plant Proteins
grains, nuts, legumes Low in saturated fat and cholesterol high in fiber, phytochemicals, vitamins, minerals and unsaturated fat Missing some “essential” amino acids Exception Soy & Quinoa
Amino acid make-up
Carbon, hydrogen, amino group (contains nitrogen), acid group, and a unique side chain
20 different side chains make 20 different amino acids (9 are essential)
How many essential amino acids are there?
9
How many non-essential amino acids are there?
11
What does conditionally essential mean?
non-essential amino acids that our body cannot make enough of or cannot produce fast enough.
Example: for wound healing.
Peptide bonds
join the acidic group of one amino acid with the amino group of another amino acid
Polypeptides
a chain of amino acids linked by peptide bonds — (3-dimensional shapes)
Dipeptide - 2 amino acids
Tripeptide - 3 amino acids
Proteins
made of one or more polypeptide chains folded into specific three-dimensional structures
Shape of Protein
essential the function
Collagen
Elongated shape
for tendons and ligaments
Hemoglobin
Spherical shape
red blood cells
Muscles
Linear shape
Denaturation
change in a protein’s three-dimensional shape
What is the process of denaturation?
Heat
Acidity
Mechanical Agitation
Making curdled milk does all three.
This change is irreversible.
Protein Functions
Structural proteins Cells Cell Membrane Organelles Cell Fluid (cytoplasm) Body Parts Skin Hair Ligaments Tendons Bones
Enzyme Protein Functions
Assist biochemical
Most chemical reactions in the body require enzymes
Transport other proteins in the blood and across membranes
Immunity/Safety functions of Proteins
Skin—barrier from bacteria
Blood clotting in case of injury
Antibodies protect the body from foreign invaders
Other Functions of Protein
Movement Muscle contraction Hormones Regulate biological processes Regulate fluid balance Maintain proper acidity of blood Energy Under certain situations
Not getting enough protein can lead to…
Immune system won’t function properly (antibodies)
Increased risk of infection, disease, sickness, even death
Tissue & cell damage… muscle, heart, liver decrease in size
Amino Acid Pool
300 grams of protein synthesized by the body.
100 from the diet
200 from recycled amino acids
Can extra amino acids be stored as protein?
No.
Extra amino acids cannot be stored as proteins
Extra amino acids are used for energy or stored as fat
Nitrogen Balance
nitrogen intake equals nitrogen loss
Maintenance of body protein and weight
Negative Nitrogen Balance
more nitrogen lost than consumed
From illness, injury, or decreased consumption
Positive Nitrogen Balance
more nitrogen consumed than lost
During growth, pregnancy, or weight training
RDA Protein
0.8 g/kilogram of body weight for adults
70 kg (154 lb) adult = 56 g of protein/day
Typical Canadian adult consumes less than 80 g of protein/day
AMDR Protein
10% to 35% of calories
UL Protein
Healthy livers and kidneys can handle is 3.5 to 4.5 g/kg of body mass per day.
How many grams of protein should we get?
We should try to get 10-20 grams of protein
4-6 times per day (15 g X 5 = 75 grams for 75 kg person)
High animal protein means
high in saturated fats and cholesterol and low in fiber
High Protein diets and increased urea output
Increased demands on the kidneys
Increased loss of water from the body
Possible increased loss of calcium
Increased risk of kidney stones
High Protein leads to an increased risk of…
heart disease
cancer (processed meats – linked to colon cancer)
obesity & diabetes
diverticulosis (outpouching of the colon wall)
North American ratio of plant and animal protein consumption.
30% Plant
70% Animal
Because of the climate.
What are the top 5 proteins consumed in North America?
Beef, chicken, milk, cheese, and bread
Incomplete Proteins vs. Complete Proteins
Do not contain all essential amino acids vs. Contain all essential amino acids.
Can combine two or more to make a complete protein.
Example: Peanut butter on whole-grain bread.
The DO’s of plant-based proteins.
DO aim for about 1 gram of protein per kg of bodyweight;
add 30-40 grams each day if you are in a phase of intense training.
DO get enough fat.
DO eat a variety of whole foods– veggies and fruits!!
The DON’Ts of plant-based proteins.
DON’T consume too many processed foods (including “healthy” protein powders and processed soy products).
What are the 2 complete plant-based proteins?
Soy and Quinoa
Benefits of Soybean Products
Soybean products are rich in protein & essential AAs
Soy milk = 8.5 g PRO;
Milk = 8.8 g PRO (same)
Soy products do not contain the ‘saturated’ fat
Soy products contain various ‘isoflavones’… which are phytochemicals (disease prevention!)
Lowering cholesterol (fiber)
Great sources of Omega 3 fatty acids (brain health)
Great source of protein (muscle, immune system, etc
Reduce the risk of prostate cancer & breast cancer (isoflavones)
Lower blood pressure by producing nitric oxide in arteries… keeps ‘open’
Simon is 26 years old and weighs 154 pounds. A year ago, he decided to stop eating meat because he thought it would make his diet healthier. Now that he is studying nutrition, he has become concerned that his vegetarian diet may not be as healthy as he thought. Simon records his food intake for one day and then uses iProfile to assess his nutrient intake. His analysis reveals that his diet provides:
2900 Calories, 78 g of protein, and 43 g of saturated fat.
Does Simon’s diet provide enough protein to meet his RDA of 0.8 g of protein per kilogram of bodyweight?
How does the percentage of calories from saturated fat in Simon’s diet compare with recommendations?
